Selective signaling system.



B. B. KLEINSCHMIDT. SELECTIVE SIGNALING SYSTEM.

APPLICATION FILED APR.7,1913.

Patented Mar. 30, 1915.

EJDWA E. KLEINSC'H a n or new roan, n. 5Z1, assisnon To name swrron a SIGNAL COMPANY, A CORPOTION 0F MAINE.

SELECTIVE SIGNALING SYSTEM.

niaaeai. original application filed teptember 8,

To all whom it may concern:

Be it known that T, EDWARD E. KLEIN SCHMIDT, aicitizen of the United States, residing at New York, borough of Brooklyn, county of Kings, and State of New York, have invented certain new and useful limprovements in Selective Signaling Systems, of which the following is a specification.

The present application is a division of my application, September 8, 1910, and the invention relates to a selective signaling system in which the selectors are bridged on a main line circuit and adapted to ground a signaling circuit. In the particular system hereinafter desdribed the selector switches are operated by turrent reversals transmitted from a central station through the bridged circuit, which circuit includes a condenser to prevent the flow of direct current through the bridged circuit. When the contacts of the selected switch are closed to ground the signaling circuit the latter will be energized by direct current from main line to ground.

Another feature of my invention relates to a slow acting magnet to control a back lash pawl or detent.

Another feature relates to ananswering back signal at the central station which is energized when the signal at the selected station is operated.

These and other features of my invention will be understood by reference to the ac-v companying diagrammatic view.

Referring to the drawing the numerals 1 and 2 indicate the conductors of a main line circuitenergized from a source of en-' ergy 3 bridged thereon. The circuit 4 includes a commutator 5, retardation coils 6, 6, and a resistance 7. The retardation coils 6, 6 on the side nearest the commutator are bridged by a condenser 8.

The particular selective apparatus shown by me is of the step-by-step type, and is operated by reversals of current on the main line circuit. For the purpose of impressing the reversals I employ at the central or dispatchers station a controller comprising a lever 9 which when in normal position closes contacts 10 included in a ground Specification of Letters Patent.

Serial No. 581,009, filed iPatented iaai. so, raw.

1910, Serial No. 581,009.- Divided and. this application filed April 7,

1913. Serial No. 75-9A83.

ed circuit 11 connected to battery. The normal position of lever 9' also maintains an open contact at 12 in the battery circuit.

When the lever 9 is moved to the right contacts 10 will be opened and contacts 12 closed thereby energizing thevmain line circuit. Upon the return movement of lever 9 to normal position the commutator 5 will be operated to impress reversals upon the main line circuit to thereby actuate the selective switches. The circuits of the selective switches are bridged onto the main line circuit, these switches comprising a pair of magnets 13-13 and a polarized armature frame 14: therefor, said frame being pivotally supported at itscenter and carrying a stepping pawl 15 adapted to engage a ratchet wheel 16. Mounted so as to rotate with the ratchet wheel is a contact 17 adapted to engage an insulated spring contact '18 carried on the armature frame 14.

prevent reverse movement of the To ratchet wheel 16 while being stepped T provide a back lash pawl 19 normally held out of engagement with the ratchet wheel by the armature 20 of a slow acting magnet21.

At each local station is a signaling device 22 which may be a bell, included in a grounded circuit 23.

When reversals are impressed on the main linecircuit the selective switches will be actuated and the circuits may be traced as follows: battery 3, commutator 5, line conductor 1, magnet 18, point 24, slow acting magnet 21, variable resistance 25 and condenser 26 to line. The initial impulse will energize magnet 21, thereby attracting its armature and permitting the spring pressed back lash pawl 19 to engage the teeth of the corresponding ratchet wheel. This being a slow acting magnet it does not respond to the interval between the reversals of the current, but retains its armature attracted until the impulses cease. When the contacts 17-1S of the switch of the selected station engage each other, grounded circuit 23 will be energized by current flowing from point 24, thereby actuating the signal 22.

The system described may be employed for any desired signaling purpose and for an illustration, T have shown it in connection til with a telephone system in which telephone equipments 27 are bridged on the main line circuit. The use 1 make of the signal 22 is to indicate to the operator at the local station that central desires tocommunicate with him, a signal device such as a lamp 28 being included in the battery circuit to indicate to the central ofiice that the desired signal has been given at the local station. I also include in the battery circuit a'normally closed switch 29 which is opened by the operator at the central station upon the coming in of the answering back signal 28. The switch 29 is only momentarily opened, and when opened magnets 13 will be. deenergized and armature 14 will be retracted by spring 30 to disengage the stepping pawl 15, from engagement with ratchetv wheel 16. When the ratchet wheel is thus disengaged the contacts 17-18 will be separated thereby opening the grounded circuit 23 and disconnecting the signal 22.

As is well known condenser 26 will only allow reversals of the current to pass through it. When, therefore, the reversals cease and the main line circuit is energized only by a continuous current, magnet 21 will be deenergized, thus permitting its armature to be retracted and pawl 19 to dis engage itself from the ratchet wheel 16. The ratchet wheel 16, however, of the selected station will be held in its stepped position by pawl 15 until the circuit is opened by switch 29 as above described. At all of the other local stations the ratchet wheel 16 will return to normal position as soon as the corresponding pawl 19 is disengaged therefrom.

The operation of the system will be clearly understood-from the foregoing description. It may be noted in particular, however, that in thepresent system the selectors instead of being in closed circuits bridged on the main line are connected in series with a condenser which closes the bridged circuit to reversals for operating the selectors and leaves it open to direct current, thereby permitting tests to be made on the circuit to locate grounds and crosses or to operate a common telephone system, as described in my application, Serial No. 581,009. It will also be noted that the signals 22 are included in grounded circuits which are normally open at the selector contacts and also open at the controller through contacts 10 while the stepping impulses are being transmittedso that the signal circuit is not established until the selector contacts of theselected signal are closed and the contacts 10 closed at the controller through the return of lever 9-to normal position. When these. contacts are closed the signaling circuit grounded;

the answeringback signal 28 is energized and it and theselcted signal 22 .remainenergized until the groundedcir uit is opened through switch 29. The direct current; for

operating the selected signal is of such p0- larity as to hold the stepping pawl 15 in engagement with the ratchet wheel, as otherwise the said wheel would return to normal position, thereby opening contacts 17-18 upon the cessation of the reversals which deenergize magnet 21.

What I claim and desire to secure by Letters Patent'of the United States is 1. In a selective signaling system, a central station, a plurality of local stations, a line circuit connectin the said stations, circuits bridged on the line at the local stations, a selector and a condenser in series therewith included in said bridged circuits and a signal at each station under the control of the selector thereat responsive only to direct current.

2. In a selective signaling system, a centralv station, line conductors, selector apparatus at a plurality of stations bridged across the line conductors, said bridged circuits being open to continuous current flow, means for impressing reversals of the current on the line to actuate the selectors and a signal at each station under the control of the selector thereat responsive only to direct current.

3. In a selective signaling system, a central station, a plurality of local stations, a

line circuit connecting said stations, selectors responsive to reversals of current and not to direct current, said selectors being bridged on the line circuit, signals at the stations controlled by said selectors and responsive to direct current, means for impressing reversals of current on the line to select a local station, means to impress a direct current on the line to operate a signal at the selected station after the Selector is set, and means to prevent the flow of direct current through the bridged circuit.

4. In a selective signaling system, a central station, a plurality of local stations, a line circuit connecting said stations, selectors bridged on the line circuit, means for impressing reversals of the current on the line to select a local station, means to impress a direct current on the line to operate a signal at the selected station after the selector is set, and a condenser in the bridged circuit to prevent the flow of direct current therethrough.

5. In a selective signaling system, a central station, a plurality of local stations, :1. line circuit connecting said stations, selectors at the local stations bridged on the line, a selector battery bridged on the line and connected to ground, means for impressing impulses on the line to select a local station, and means for opening said'grounded circuitwhile said impulses are on the line.

6. In a selective signaling system, a central station, a plurality of local stations, a

line circuit connecting said stations, selectors meager responsive to reversals of current and not to direct current, said selectors being at the local stations bridged on the line, signals at the stations controlled by said selectors and responsive to direct current, a signaling circuit at each local station connected to ground and adapted to be closed by the selector, a selector battery bridged on the line and connected to ground, means for impressing impulses on the line to select a local station, and means for opening the grounded battery circuit while said impulses are on the line.

7. In a selective signaling system, a central station, a plurality of local stations, a line circuit connecting said stations, selectors at the local stations bridged on the line, a signaling circuit connected to ground at each local station, a selector battery at the central station bridged on the line and con nected to ground an answer-back signal included in said ground connection at the central station and means for simultaneously grounding the selected local signaling circuit and the battery circuit.

8. In a selective signaling system, a central station, a plurality of local stations, a line circuit connecting said stations, selectors at the local stations bridged on the line, a selector battery bridged on the line and connected to ground, and means for opening said ground connection and for impressing impulses on the line to set a selector.

9. In a selective signaling system, a central station, a plurality of local stations, a line circuit connecting said stations, selectors direct current, said selectors being at the local stations bridged on the line, signals at the stations controlled by said selectors and responsive to direct current, a selector battery bridged on the line and connected to ground, and means for opening said ground connection and for impressing impulses on the line to set a selector, a signaling circuit at each local station connected to ground, and means controlled by the selector to ground to corresponding signaling circuit.

10. In a selective signaling system, a central station, a plurality of local stations, a line circuit connecting said stations, selectors at the local stations at the central station bridged on the line, a selector battery bridged on the line and connected to ground, means for opening said ground connection and for impressing impulses on the line to set a selector, a signaling circuit connected to ground at each local station, and means for grounding the battery and the local signaling circuit on the cessation of the impulses to thereby permit of the operation of the signal by direct current.

11. lln a selective signaling system, a central station, a plurality of local stations, a line circuit connecting said stations,selectors bridged on the line and non-responsive to direct current, a selector battery bridged on the line. and connected to ground, a controller comprising means to open said ground connection and to impress impulses on the line to set a selector, a signaling circuit at each local station connected to ground and adapted to be closed by the selector to thereby actuate the signal by direct current when the selector is set.

12. In a selective signaling system, a central station, a plurality of local stations, a line circuit connecting said stations, selectors bridged on the line and non-responsiveto direct current, means for impressing impulses on the line to set a selector, a signal at each local station included in a grounded circuit normally open at the selector and open at the controller While the setting impulses are on the line, and means for closing said breaks in the signaling circuit when the selector is set to thereby impress a direct current on the line to operate the signal.

13. In a selective signaling system, a central station, a plurality of local stations, a line circuit connecting said stations. a selector battery bridged on the line and connected to ground, selectors bridged on the line and I circuit, a contact in said last-named circuit responsive to reversals of current and not to adapted to be closed by the selector, a controller for impressing reversals of current on the line to set a selector, and contacts in said battery ground connection closed when the controller is in normal position to thereby close the signal circuit to direct current.

EDWARD E. KLEINSCHMIDT.

Witnesses M. E. MoNrNcH,

CHARLES S. Jones. 

